Lifting equipment



Oct. 20, 1970 J. M. EITEL LIFTING EQUIPMENT 2 Sheets-Sheet 1 Filed Sept. 22. 1967 INVENTOR.

Jay M Eire! Attorneys Oct. 20, 1970 J. M. ElTEL 3,534,868

LIFTING EQUIPMENT Filed Sept. 22, 1967 2 Sheets-Sheet Z M Fig.2

INVENTOR.

Jay M. Eire! Z 4, 34 1 2,04 0124i, 40% Q flu Attorneys United States Patent O 3,534,868 LIFTING EQUIPMENT Jay M. Eitel, Atherton, Califl, assignor to General Cable Corporation, a corporation of New Jersey Filed Sept. 22, 1967, Ser. No. 669,829 Int. Cl. B66c 23/84 US. Cl. 212--66 7 Claims ABSTRACT OF THE DISCLOSURE Lifting equipment having a platform with a boom rotatably mounted thereon and drive means for rotating the boom including a circular drive structure having an outwardly facing exterior, substantially circular driving surface and a drive member contacting the exterior circular driving surface.

BACKGROUND OF THE INVENTION This invention relates to lifting equipment and more particularly to lifting equipment of the type which is adapted to be mounted upon a mobile platform. In application Ser. No. 521,193, filed Jan. 17, 1966, now abandoned in favor of continuation-in-part application Ser. No. 697,887, filed Jan. 15, 1968, which has matured into Pat. No. 3,437,175, issued Apr. 8, 1969, there is disclosed a lifting equipment which has many advantages over lifting equipment or apparatus which was theretofore previously available. However, even with the lifting equipment shown in said application Ser. No. 521,193, there is still a need to further simplify the construction of the lifting apparatus so that it can be produced more economically.

SUMMARY OF THE INVENTION AND OBJECTS The lifting apparatus consists of a platform and a support structure. The support structure is rotatably mounted upon the platform for rotation about a vertical axis. A boom structure is mounted upon the support structure for movement about a substantially horizontal axis and drive means is carried by the platform and support structure for causing rotation of the support structure about the vertical axis. The drive means includes a circular drive structure having an exterior, substantially circular driving surface. The drive means also includes at least one drive member in contact with the exterior, outwardly facing surface of the drive structure. Means is provided for rotating the drive member to cause its movement on the exterior, outwardly facing surface of the drive structure to thereby cause rotation of the boom structure relative to the platform.

In general, it is an object of the present invention to provide a lifting apparatus which is of a simplified construction.

Another object of the invention is to provide a lifting apparatus of the above character in which the frictional engagement between the driving members is increased as the loading on the boom structure is increased.

Another object of the invention is to provide a lifting apparatus of the above character in which the rotational drive gear for the boom structure is located underneath and close to the pivot for the boom structure.

Another object of the invention is to provide a lifting apparatus of the above character in which the torsional load of the rotation mechanism is distributed over a large diaphragm.

Another object of the invention is to provide a lifting apparatus of the above character in which the diaphragm serves as a protective cover.

Additional objects and features of the invention will appear from the following description in which the pre- Patented Oct. 20, 1970 ferred embodiment is set forth in detail in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENT The lifting equipment consists of a self-propelled vehicle 11 having front and rear wheels 12 and 13 rotatably mounted on a chassis or framework 14. The self-propelled vehicle 11 is provided with suitable motive means (not shown) for supplying power to the wheels of the vehicle. A platform or bed 16 is provided upon the chassis or framework 14. A cab 17 of a conventional type is mounted on the front end of the chassis and is provided with a driving station for the driver of the vehicle.

A lifting apparatus 21 is mounted on the self-propelled vehicle. The lifting apparatus 21 consists of a support structure 22 which has its lower end rotatably mounted upon the platform '16 by a self-aligning ball or roller bearing 23. The bearing 23 is mounted upon the platform in any suitable manner as, for example, it can be mounted upon a plate 24- which is secured to cross members 26 secured to the chassis 14 of the vehicle. The support structure 22 can be tubular in form. However, this form is not necessary because there is no torsion placed on member 22 as hereinafter explained. However, as shown in FIG. 1 of the drawing, the support structure 22 can be formed with an inverted cone-shaped portion 22a which is secured to the bearing 23, a cylindrical portion 22b, an outwardly tapered portion 220, and a larger cylindrical portion 22d.

A boom structure 41 also forms a part of the lifting apparatus 21 and, as shown in the drawing, can be in the form of telescoping ladders as hereinafter described. The boom structure 31 is, in general, provided with a main or outer ladder section 32 and an inner or telescoping section 33. Means is provided for pivotally mounting the main section 32 of the boom structure 31 upon the support structure '22 for movement about a substantially.

horizontal axis and consists of a rigid framework 36 which is secured to the upper portion 22d of the support structure 22 by suitable means such as welding. The main section 32 is secured to the framework 36 by pins 37 mounted on opposite sides of triangularly shaped plates 38 carried by the framework 36.

Means is provided for raising the outer or free end of the boom structure 31 or, in other words, for swinging the outer or free end of the boom structure about the horizontal axis provided by the pins 37. As shown in FIG. 1, such means takes the form of a hydraulic actuator 41 which includes a cylinder 42 that is pivotally mounted upon a cross-bar 43 mounted Within the support structure 22 and a piston rod 46 that is pivotally connected to the main section 32 by a pivot pin 48. It can be seen that the support structure 22 has an inner diameter which is sufficient to permit tilting of the hydraulic actuator 31 about the pivot pin 44 carried by the bar 43 as the boom structure 41 is raised and lowered by operation of the hydraulic actuator 31.

Drive means is provided for rotating the support structure 22 and the boom structure 31 carried thereby about a substantially vertical axis and consists of a circular track structure -51 which is provided with an exterior, outwardly facing circular surface 52. As shown in FIGS. 1 and 2 of the drawing, the track structure 51 is in the form of a large pneumatic tire of a suitable diameter such as 3 or 4 ft. In heavy duty application, it is preferable that the tire be molded with a plurality of vertical grooves 53 extending in a direction parallel to the axis of the tire and which simulate gear-like tread. The track structure or tire 51 is mounted upon an annular rim 56 which is secured to the upper flanged end of a tubular member 57 which surrounds and encompasses the support structure 22. The lower extremity of the tubular member 57 is secured to the plate 54 by suitable means such as welding or, alternatively, can be secured directly to the chassis of the vehicle. From FIG. 1, it can be seen that the tubular member 57 is concentric with the support structure 22.

The drive means for rotating the boom structure 41 also includes at least one drive member 59 which engages the track structure 45. As shown particularly in FIGS. 1 and 2, the drive member 59 is in the form of a metal gear which is provided with teeth 61 which are adapted to travel in the grooves or tread 43 provided in the track structure 51. As can be seen from FIG. 1 the exterior surface 52 of the track structure 51 is disposed in a vertical direction. Similarly, the drive member 59 is disposed in a vertical direction and is mounted on a shaft 62 driven by a gear motor 63 carried by the framework 36.

If desired, additional means can be provided for centering the framework 36 with respect to the track structure 51. Thus, as shown, three separate idlers 66, 67 and '68 have been provided and which are spaced apart 90 from each other. The idlers 66 and 67 are mounted on shafts 69 carried by blocks 71 mounted in extensions 72 provided on the sides of the framework 36. The idler 68 is mounted on a shaft 73 which is secured to the forward end of the framework 36.

As pointed out previously, the boom structure 41 consists of a main section 42 and a telescoping section 43. The boom structure can be of the type described in application Serial No. 521,193, filed Jan. 17, 1966, now abandoned in favor of continuation-in-part application Ser. No. 697,887, filed Jan. 15, 1968, which has matured into Pat. No. 3,437,175, issued Apr. 8, 1969. Alternatively, as shown in the drawing, the boom structure can be of the telescoping ladder type which is provided with a plurality of rungs 76 to permit a workman to climb the boom structure and to enter a workmans platform 77 mounted on the outer end of the telescoping section 43. As shown in FIG. 1, the workmans platform 77 can be of a conventional type such as a three-step platform so as to provide a relatively level surface for the workman to stand on regardless of the elevation of the boom structure. Hand rails 78 are also mounted on the outer end of the telescoping section 33 so that the workman can grasp the same while he is standing on the platform 77. The ladder type boom structure 31 is of a conventional type and the telescoping section 33 is telescoped with respect to the main section 32 by a drive motor 79 which drives an extension drive chain 80 for extending and retracting the telescoping section 33.

Control means is provided for controlling the operation of the boom structure 31 either from the workmans platform 77 or from the bed 16 of the Vehicle itself. Such control means is described in Pat. No. 3,136,385 and, as disclosed, may include a control mechanism 81 which is mounted on the outer end of the telescoping section 33 so that it can be grasped by a workman in the workmans platform 77. If desired, the control mechanism 81 can be pivotally mounted on the telescoping section 33 so that it is always in a generally vertical direction to facilitate its operation by the workman on the workmans platform irrespective of the angular position of the boom structure 31.

A ladder 86 is mounted upon the support structure 22 and extends downwardly from the rim 46 to a position adjacent the platform 16 so that a workman on the bed of the vehicle 16 can mount the ladder and climb onto the boom structure 31.

Operation and use of a lifting equipment may now be briefly described as follows. Let it be assumed that the operator who is driving the vehicle advances the vehicle 11 to the desired location. The workman then steps from the operators driving station in the cab 17 onto the ground and climbs onto the bed 16 of the vehicle, then climbs the ladder 86 and walks down the rungs 76 of the boom structure 31 assuming that the boom structure 31 is in the solid line position as shown in FIG. 1. The workman continues until he reaches the end of the boom structure and then enters the workmans platform 77. Thereafter, the workman can grasp the control mechanism 81 to locate the workmans platform 78 in the desired position by controlling the movement of the boom structure 31. As described in Pat. No. 3,136,- 385, the control mechanism 81 can be operated to individually or simultaneously operate the means for extendand and retracting the telescoping section 33 by energizing the extension drive motor 79 for moving the outer end of the boom structure 31 in clockwise and counterclockwise directions by energization of the gear motor 63 and for raising and lowering the outer end of the boom structure about a horizontal axis formed by the pins 37 by actuating a hydraulic pump (not shown) for supplying fluid to the hydraulic actuator 42 or by bleeding fluid from the hydraulic actuator 42. As explained in copending application Ser. No. 521,193, filed Jan. 17, 1966, in place of the hydraulic actuator 42, an electrically operated ball screw jack assembly 73 can be provided for accomplishing the same function. Thus, it can be seen that the operator can readily position the workmans platform 77 in any desired location. After the operator has completed his work, the workman can again lower the boom structure to the position shown in solid lines in FIG. 1 and can dismount therefrom by using the rungs of the ladder sections and the ladder 86. The operator can then dismount from the bed 16 and enter the cab of the vehicle and drive the cab to the next location at which it is desired to perform work.

When the boom structure is being rotated about a vertical axis, the drive member or gear 59 is rotated about the stationary tire which forms the track structure 41. As the boom structure is extended or as greater weight is placed on the upper end of the boom structure, it can be seen that there will be a tendency to place a bending moment on the substantially cylindrical support structure 22 which will cause it to shift to one side of the outer tubular member 57. As this movement occurs, the pinion gear or drive member is further pressed into the tire which forms the track structure 51. Thus, with the greater extension or the greater weight on the outer end of the boom structure, more pressure is applied between the pinion gear and the tire to increase the traction between the same. With this arrangement, as the bending moment is increased on the support structure 22, the traction capabilities of the drive mechanism are increased.

Because of this increased traction capability which is provided with increased loading on the boom structure, it is possible that a smooth surface pinion roller can be provided in place of the pinion gear 62 and that the tire or track structure 41 can also have a relatively smooth surface. It is only necessary that there be suflicient friction between the pinion roller and the exterior surface of the tire to cause rotation of the boom structure about the vertical axis.

The self-aligning ball hearing or roller bearing 23 readily accommodates the relatively small shifting of the movement of the upper end of the support structure 22 relative to the bearing 23.

The tire which serves as the track structure 51 can have any desired amount of resilience. For example, it can be filled with air or, if desired to give less resilence to the tire, the tire can be filled with water or other suitable liquid.

Although three separate idlers have been provided in addition to the drive member 59, it can readily be appreciated that it would be possible to build a lifting equipment without utilizing any idlers and that in any event it would be possible to reduce the idlers to two in number with the idlers being separated by 120 from the drive pinion 59.

From the construction disclosed above, it can be seen that the rotating mechanism is constructed in such a manner that it is relatively low in cost. Substantially all critical machine work or machine parts have been eliminated. Also, there is no necessity for parts having close tolerances.

In the arrangement shown in FIGS. 1 and 2, the rotational drive means which includes the gear motor 63 and the drive pinion 59 is located underneath and in close proximity to the horizontal pivot for the boom structure 31. This facilitates the fabrication of an economical steel structure because the loads are concentrated into a localized area.

What is claimed is:

1. In lifting equipment, a platform, a support structure, means rotatably mounting the support structure upon the platform for rotation about a vertical axis, a boom structure mounted on the support structure for movement about a substantially horizontal axis, power means within said support structure for raising and lowering said boom structure about said horizontal axis, a resilient tire encircling said support structure, means mounting said resilient tire on said platform in a fixed position, said means for mounting said resilient tire including a framework which generally surrounds said support structure and supports said resilient tire at a level adjacent the upper extremity of the support structure, said resilient tire having an outwardly facing drive surface, a drive member frictionally engaging the exterior of the outwardly facing drive surface, means mounting said drive member on said support structure, and power means for causing rotation of said drive member to cause the same to travel about the exterior outwardly facing drive surface to thereby cause rotation of the outer end of the boom structure about said vertical axis.

2. A lifting equipment as in claim 1 wherein the exterior outwardly facing drive surface of the resilient tire is provided with a gear-like tread and wherein said drive member is in the form of a pinion gear engaging said gear-like tread.

3. A lifting equipment as in claim 2 wherein said framework includes a tubular member aifixed to the platform and which surrounds at least the lower extremity of the support structure.

4. In a lifting equipment, a platform, a support structure, means rotatably mounting the support structure upon the platform for rotation about a substantially vertical axis, a boom structure mounted on the support structure for movement about a substantially horizontal axis, and drive means for rotating the support structure and the boom structure carried thereby about a vertical axis, said drive means including a track structure rigidly secured to said platform and having an exterior, outwardly facing drive surface, the drive member frictionally engaging the exterior, outwardly facing drive surface of the track structure and motive means carried by the support structure for driving said drive member and to cause the same to travel about the exterior, outwardly facing drive surface of the track structure to cause rotation of said outer end of the boom structure about said vertical axis, said drive means including a framework affixed to the platform and which surrounds at least the lower extremity of the support structure, a tire rim mounted on the upper extremity of said framework and a tire formed of resilient material mounted on said rim and forming the outwardly facing exterior surface.

5. A lifting equipment as in claim 4 together with means mounted in the support structure for raising and lowering said boom structure about the horizontal axis and means carried by the boom structure for extending and retracting the boom structure.

6. A lifting equipment as in claim 5 together with idler rollers carried by the support structure and engaging the exterior, outwardly facing drive surface of the track structure.

7. In a lifting equipment, a platform, a vertically extending support structure having a substantially open upper end, means rotatably mounting the support structure upon the platform for rotation about a vertical axis, a boom structure mounted on the upper end of said support structure for movement about a substantially horizontal axis power means mounted in said upper end of said support structure for raising and lowering said boom structure about said horizontal axis a framework mounted upon the platform and generally surrounding said support structure, a track structure rigidly secured to said framework at a position generally adjacent the upper extremity of the support structure, said track structure having an exterior, outwardly facing drive surface, a drive member engaging the exterior of the outwardly facing drive surface, means mounting said drive member on said support structure, and power means mounted on said support structure for causing rotation of said drive member to cause the same to travel about the exterior, outwardly facing drive surface to thereby cause rotation of the outer end of the boom structure about said vertical axis.

References Cited UNITED STATES PATENTS 2,965,244 12/1960 Schat 21268 2,414,573 1/1947 Wagner 21270 2,838,183 6/1958 McIntyre 212-68 2,996,141 8/1961 Eitel 182-2 3,215,411 11/1965 Pitts 74207 FOREIGN PATENTS 650,830 3/1928 France.

HARVEY C. HORNSBY, Primary Examiner US. 01. X.R. 

